Philo Power Plant

Philo Power Plant

Company type	Coal-fired power plant
Industry	Electric power generation
Founded	1924 in Philo, Ohio, United States
Defunct	1975
Fate	Demolished in 1983
Headquarters	Philo, Ohio , United States
Area served	Ohio, United States
Products	Electricity
Owner	Ohio Power (predecessor of American Electric Power)
Number of employees	203 (1975)

The Philo Power Plant was a coal-powered facility with a generating capacity of 510 megawatts (MW), situated in Philo, Ohio, within Muskingum County, Ohio. It holds the distinction of being the first plant in the United States to incorporate both steam reheat and supercritical steam generator technologies in its turbine systems. The plant was owned and managed by Ohio Power, a forerunner of American Electric Power (AEP), and it operated from its inception in 1924 until its shutdown in 1975.

History

The plant's construction commenced in 1922, following designs by Sargent & Lundy. Unit 1 began commercial production in 1924, originally rated at 35 MW using a General Electric Curtis turbine, which was subsequently upgraded to 40 MW after successful performance trials. This unit was pioneering for implementing steam reheat technology at a peak pressure of and temperatures approaching . In 1957, Unit 1 was decommissioned and replaced by Unit 6. Unit 2 came online in 1925 with an identical output of 40 MW. The combined expenditure for Units 1 and 2 amounted to $10 million.

The completion of Unit 3 in 1929 marked a substantial increase in capacity to 165 MW, with construction costs totaling $17 million. During the early 1940s, Units 4 and 5 were commissioned, each contributing an additional 85 MW to the plant's output.

Philo Unit 6

Unit 6 at Philo was notable as the first commercially operational supercritical steam generator in the country, commencing service in 1957 with a capacity of 120 MW. Its steam generator, manufactured by Babcock & Wilcox, operated at a maximum pressure of and temperature around . The steam turbine, engineered by General Electric, functioned at a rotational speed of 3,600 rpm. Although it achieved ultrasupercritical conditions during testing, material constraints limited continuous operation at these parameters. The unit featured a dedicated smokestack and required an investment of roughly $19.5 million.

Operations

Upon startup, the plant achieved a thermal efficiency of approximately 24%, utilizing about 14,000 BTU per unit of electricity produced. Coal supplies were delivered primarily via rail or river barge, sourced mainly from Ohio mines with some from West Virginia. Water for cooling was drawn from the Muskingum River upstream of a dam and returned downstream after use. At the time of shutdown, the facility employed a workforce of 203 individuals.

Closure and demolition

The Philo Power Plant ceased operations on May 31, 1975, influenced by reduced electricity demand amid the economic downturn between 1973 and 1975 and competition from newer, more efficient power stations. Following closure, it remained on standby status with one unit maintaining voltage regulation while Ohio Power evaluated potential reactivation options. The structure was ultimately demolished in 1983. Components from Unit 6’s turbine rotors were transformed into an art installation by George Greenamyer that same year, becoming part of the landscape design for the newly constructed AEP Building in Columbus.

See also

• List of power stations in Ohio